The present invention relates to a composition for and a method of providing thermal insulation and fire-resistance to buildings by filling voids or spaces in and around structural members with a low density thermally insulating and fire-resistant cementitious composition containing a high proportion of a relatively smooth-surfaced, vesicular, expanded perlite, referred to hereinafter simply as "expanded perlite". The method includes using at least one flexible, woven, fire-resistant bag as a containment vessel which allows the novel cementitious composition to fill the space by conforming itself and the containment bag to the shape of the space while simultaneously containing the cementitious composition in the desired position until it is cured. The method is particularly directed to remedial, post-construction applications in occupied buildings.
In prior fire-proofing or fire-safing compositions, simultaneously obtaining strength, light weight and fire resistance has been particularly difficult, since known lightweight fire-resistant materials are generally very soft and easily broken apart.
In prior cementitious compositions, it has been very difficult to obtain good resistance to high heat in any concrete or cementitious composition. It has been difficult to obtain a strong and light weight concrete.